A combustion pipe holder or an oxygen lance with a lance holder is familiar, for example, from EP 0 372 099 B1. However, only a thread is indicated at the oxygen intake of this lance holder onto which a safety pipe that is not shown here is screwed. Such safety pipes or safety sections, mainly made of stainless steel, are helpful with hand-operated lance holders and serve above all to increase operational safety, because they are intended to achieve the perfect introduction of the flammable gases, above all of the oxygen, through into the lance holder. However, it is difficult if the coupling device between the oxygen lance and the safety section or the safety pipe is handled carelessly and the coupling device is not tightened sufficiently, because it may happen that the highly flammable gas escapes. For this reason it is important that the coupling device is always fastened tightly in order to guarantee the seal tightness of the connection. However, in case of carelessness the described danger is still present.
The invention is therefore based on the problem of creating a coupling device above all for oxygen supply pipes in steel works with which dangerous leaks are approximately avoided, even, where possible, completely ruled out.